<input type="text" name="token" inputmode="numeric" pattern="[0-9]" autocomplete="one-time-code" />

body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #efefef;
}
input {
  font-size: 2rem;
  padding: 1rem;
}